What does the research say? A deeper dive into the evidence for scuba diving and mental health

At DepthWorks, we know our treatment works. The people who come to us tell us so — and the independent evidence we have collected so far backs them up. But we are also genuinely curious about the science behind what we do. Why does diving at depth seem to help? What is it about this experience that can shift something so deeply held as trauma?

To try and answer those questions, we have been reading. Over the past few years, a small but growing group of researchers has been looking at how scuba diving might support people living with PTSD, stress, anxiety and other mental health challenges. The studies are small, the methods vary, and the science is still early — but the signals are consistent, and they point in an encouraging direction.

Here is a plain-language tour through five of the studies that have most shaped our thinking. If you want to read the original papers, links are in the footnotes.

Johns Hopkins (2011): the study that started it all for us

In 2011, Dr Adam Kaplin at Johns Hopkins University and Dr Daniel Becker at the Kennedy Krieger Institute ran a small pilot study with ten wheelchair-dependent veterans. The veterans completed a four-day open-water scuba certification alongside able-bodied dive buddies. Eight made it all the way through the protocol. The researchers measured a range of physical and psychological outcomes before and after.

The physical findings were modest but real — reduced muscle spasticity, improved sensory response. But it was the mental health findings that turned heads. Participants reported an approximately 80% reduction in PTSD symptoms. The control group, who did not dive, showed no equivalent change.

This was one of the first peer-reviewed studies to suggest that scuba diving could have a meaningful impact on PTSD symptoms, and it is the study that set Kevin, the originator of the DepthWorks protocol, on his path. He read a summary of it in Diver magazine and decided to see if the results could be replicated and improved on. Fourteen years later, here we are.

Kaplin and Becker, 2011. Read the summary article.

Beneton and colleagues: diving as a way to manage stress

Not every study has looked at PTSD specifically. Some have asked a broader question — does scuba diving help people manage stress? Beneton and colleagues compared 37 people who took a one-week scuba diving course (two dives a day, down to 40 metres) with 30 people who did a multi-sport week of kayaking, hiking and climbing.

Both groups felt better afterwards — mood and wellbeing improved across the board. But the divers reported a significant reduction in perceived stress that the multi-sport group did not, and that reduction held up at one-month follow-up. The divers also showed greater gains in mindfulness, and a reduced sense of disconnection from their bodies.

That last point caught our attention. Many people living with trauma describe feeling cut off from their own bodies. A one-week diving course was enough to shift that — even in people who were not presenting with PTSD.

Beneton et al. Read the paper.

Bathysmed: diving with survivors of the 2015 Paris attacks

The Bathysmed study took 34 survivors of the 2015 Paris terrorist attacks through a six-day programme in Guadeloupe, combining structured scuba diving with mindfulness and breathing techniques. They compared outcomes with a multi-sport control group, measuring PTSD symptoms and mindfulness before, immediately after, and then at one and three months.

The Bathysmed group generally did better than the control group, and one finding reached statistical significance — a meaningful reduction in PTSD intrusion symptoms (the flashbacks and unwanted memories that are often among the most distressing features of the condition) at one month post-treatment. However, the benefits faded over time, which tells us something important: a six-day intervention, on its own, may not be enough for sustained change.

This is part of why our protocol is longer — 10 to 14 days — and why we pay such close attention to what surrounds the dives, not just the dives themselves. Read the paper.

Krpalek: does adding therapy to diving help?

Krpalek and colleagues asked a natural follow-up question: if diving alone seems to help, does adding structured therapeutic support on top of it help even more? They worked with 15 male veterans, split into two groups. Both groups did two ocean dives over three weeks. One group also received occupational therapy — breathing techniques, group discussions, journaling — alongside the diving.

Both groups improved on measures of PTSD, depression, stress, and occupational performance. But the group that received the additional therapy showed a small, statistically significant improvement in anxiety that the diving-only group did not.

For us, that is a useful nudge. Diving seems to do a lot of the heavy lifting on its own. But the space we create around the dives — the unhurried evenings, the time to reflect, the careful attention — may well be adding something meaningful on top.

Krpalek et al. Read the paper.

Morgan: what do veterans actually say about it?

Numbers only tell part of the story. Morgan's team took a qualitative approach, working with 15 male veterans — some amputees, some dealing with co-occurring mental health and anxiety — to understand what scuba diving actually felt like from the inside. They used interviews and observation alongside a standard mental health questionnaire (the GHQ-28).

The veterans described diving as mood-lifting and relaxing. They reported feeling more confident, and spoke about an improvement in their broader sense of wellbeing. Their GHQ-28 scores shifted by 14.3 points — a substantial and clinically meaningful reduction in symptoms.

The authors concluded that scuba diving shows real promise as a therapeutic activity for veterans facing physical or psychological challenges. What we take from it is slightly different. What Morgan's participants described — the relaxation, the confidence, the reconnection — is exactly what the people who come to us describe. We are not seeing something unique to Long Island. We are seeing something the water does.

Morgan et al. Read the paper.

So what does all this add up to?

Taken together, these five studies tell a consistent story. Scuba diving — whether short or longer, with or without added therapy, with veterans or with civilians — seems to reduce PTSD symptoms, lower stress, improve mood, build confidence, and reconnect people with their bodies and with the present moment. The findings are not yet large enough or standardised enough to be called definitive. But they are consistent. And they point the same way.

What they do not yet explain is why. Is it the breathing? The weightlessness? The quiet? The focused attention diving demands, which leaves no room for intrusive thoughts? Is it the effect of nitrogen at depth on brain chemistry? Is it the simple fact of being somewhere beautiful, far from the context in which the trauma took root? Probably it is several of these things at once — and teasing them apart is one of the questions we are most interested in.

The DepthWorks protocol goes deeper, longer, and with more structured care around the dives than any of the studies above. We think that matters. We see results that go well beyond what the literature has reported so far, and those results last. We are working on building the evidence base to show that — carefully, ethically, and in partnership with researchers who can help us ask the right questions.

The science is catching up with what our participants already know: something about diving at depth can loosen the grip of trauma. Our job is to keep learning why — so that more people can feel it for themselves.

What we are working on next

We are building on this evidence base in three ways. We are sharpening the questionnaires we use with the people who come to us, so we can track change in PTSD, OCD, anxiety, depression, and addiction symptoms with greater precision. We are looking for academic partners interested in running a clinical trial on the DepthWorks protocol. And we are exploring whether the same effect can be achieved in other settings — such as deep swimming pools — to help us understand what is really doing the work.

If you are a researcher, a clinician, or someone living with PTSD who would like to know more, we would love to hear from you. Get in touch.

References

(1) Kaplin, A. and Becker, D. (2011). Johns Hopkins / Kennedy Krieger pilot study. medicalxpress.com.

(2) Beneton, F. et al. Recreational scuba diving as a stress-management intervention. pmc.ncbi.nlm.nih.gov.

(3) Trousselard, M. et al. The Bathysmed protocol with survivors of the 2015 Paris attacks. tandfonline.com.

(4) Krpalek, D. et al. Occupational therapy and scuba diving for veterans. journal-veterans-studies.org.

(5) Morgan, A. et al. Qualitative service evaluation of scuba diving with veterans. tandfonline.com.